The present invention relates to a kitchen treating apparatus of the type known as kitchen robot or apparatus for preparing food, enabling to achieve various kitchen duties by action of a set of interchangeable tools driven in rotation by an electrical motor, the shaft of which being provided with means allowing to receive each tool.
The various specialized functions such as rasping, chopping or cutting of fruits or vegetables, are each achieved by a rotary tool, generally in form of a disk, disposed at the upper part of a working bowl or vessel. The products are introduced through a hopper.
Due to the high speed of the driving shaft, whether this shaft is the motor shaft itself or the output shaft of a step-up or a reducing gear, it is necessary that the fixing of the tool on the shaft be rigid enough for supporting the important strains it is subject to.
Various means are known for connecting a tool on the end of a shaft. A first solution consists in forming the tool with a central opening in which is projecting the driving shaft end which is provided with a thread cooperating with a suitable nut for locking the disk on a shoulder formed on the shaft. Although it is cheap, this fixing is not satisfactory, since the strength with which the user screws the nut on the shaft is quite changeable so that the tool is practically always unproperly fixed, the nut being too or unsufficiently tightened. Further, the two threaded parts may present seizing what makes the disassembling difficult if not impossible . According to a second solution, the tool is snap engaged on the shaft end. A supplementary special tool is then necessary for the disassembling.
According to another solution, each tool is provided with a cylindrical hub surrounding the shaft on a substantial length the inner section of the hub being complementary of the shaft end outer section. For example, the shaft end may be formed with a flat spot, the hub inner section presenting a corresponding flat wall. The hub is generally made of plastic material, such as polycarbonate, and the assembly disk-hub is achieved by in-moulding. For evident practical grounds, the steel sheet forming the disk should be relatively thin, generally about 1/2 mm, and it needs to be stiffened. That may be achieved by forming radial ribs, e.g. three, what will allow a driving without sliding between hub and disk. The moulded hub is surrounding the radial ribs near the center. This solution also has drawbacks. One is the high cost of each tool. Another drawback is due to the ribs, forming a hollow groove in the upper tool surface, but a projecting rib on the bottom surface. When a slice is cut by a chopping blade said slice passes under the disk and is hit by the rib rotating at a high speed, before falling down in the bowl. If the cut fruit or vegetable is tender (a tomato for example), the cut slice is crushed and the appearance is not nice.
Another problem solved by present invention is the storage of the tools in suitable places for being ready to use, what is particularly difficult to achieve when each tool disk is fitted with a hub, and when there are many tools although only one is needed at a time.